Week 6 Flashcards
What are the two components of the trigeminal nerve?
- Motor root
2. Sensory root
Where does the motor root of the trigeminal nerve arise?
- In the pons
2. Anteromedial to the sensory root
The motor root of the trigeminal nerve is more compact than the sensory root. True or False.
True
How does the motor root of the trigeminal nerve travel to the trigeminal cave?
It passes as a separate structure with the sensory root through the dura to reach the trigeminal cave.
The motor root passes ABOVE the sensory trigeminal ganglion WITHOUT SYNAPSING and through FORAMEN ROTUNDUM. True or False.
False. The motor root passes UNDER the sensory trigeminal ganglion WITHOUT SYNAPSING and through FORAMEN OVALE.
Where does the motor root of the trigeminal nerve unite with the sensory root?
In or just below the foramen ovale.
What does the sensory root of the trigeminal nerve connect with?
Pons and trigeminal ganglion
What does the sensory root of the trigeminal nerve consist of in the trigeminal ganglion?
Central processes of unipolar neurons
What type of ganglion is the trigeminal ganglion?
Sensory
Trigeminal neurons are bipolar. True or False.
False, they are unipolar
What are the characteristics of a unipolar neuron?
- Have just a single axon like process arising from the cell body
- This process divides adjacent to the cell body to form a central process to the CNS and a peripheral process
Where do the peripheral processes bring information to the neurons of the trigeminal ganglion?
From structures supplied by the three divisions of the trigeminal ganglion. (i.e. most of the sensory fibres in the three divisions of the trigeminal are peripheral processes of trigeminal neurons in the trigeminal ganglion)
Which axon does not have their cell body in the trigeminal ganglion? Where are they located instead?
The proprioceptive axons of the muscle of mastication. Instead the cell bodies are located in one of the sensory nuclei of the trigeminal in the pons (mesencephalic nucleus)
What are the three divisions of the mandibular nerve?
- Trunk
- Anterior division
- Posterior division
What does the trunk of the mandibular nerve consist of? (2)
- Meningeal branch
2. Medial pterygoid nerve
What does the meningeal branch pass through? What else passes through this?
Foramen spinosum
Middle meningeal artery
What does the meningeal branch supply? (2)
- Meninges of middle cranial fossa
2. Mastoid air cells.
Where on the trunk of the mandibular nerve does the medial pterygoid nerve arise?
On the posterior surface
What does the medial pterygoid nerve immediately do?
It immediately gives off a branch which inserts into the medial surface of the medial pterygoid muscle.
What does the medial pterygoid nerve have near the origin?
Two tiny branches:
- Tensor palati
- Tensor tympani nerves
What does the tensor palati nerve enter?
Medial surface of tensor palati muscle
What does the tensory tympani nerve enter? What does it supply?
A minute bony canal to supply tensor tympani in wall of middle ear
What are the two branches of the anterior division of the mandibular nerve?
- Nerve supplying muscles of mastication
2. Sensory buccal nerve
The nerves supplying muscles of mastication enters the superficial surface of muscles. True of False.
False, it enters the deep surfaces of muscles
What are the nerves supplying muscles of mastication?
- Masseteric nerve
- 2-3 deep temporal nerves
- Lateral pterygoid nerve
What do branches of the mandibular nerve to all muscles and to medial pterygoid trunk carry?
- Motor fibres (from motor root of trigeminal)
2. Sensory fibres (including proprioceptive)
Where does the sensory buccal nerve pass?
Passes between 2 heads of the lateral pterygoid, then runs medial to tendon of temporalis and coronoid process.
Where does the sensory buccal nerve send it sensory fibres to?
- Cheek
- Buccal mucosa
- Buccal gingiva over mandibular molars
Where does the buccinator get its motor and sensory innervation from?
Motor: Buccal branch of facial nerve
Sensory: Uncertain
What are the three divisions of the posterior division of the mandibular nerve?
- Auriculotemporal
- Lingual
- Inferior alveolar
The posterior division of the mandibular nerve is mostly sensory. What is the exception?
Mylohyoid nerve which is motor
What is the auriculotemporal nerve?
Cutaneous sensory nerve
What is close to the origin of the auriculotemporal nerve?
Otic ganglion
What is the otic ganglion?
Parasympathetic ganglion of the glossopharyngeal nerve, situated just below the foramen ovale
What does the auriculotemporla nerve pick up? Where does it transmit them?
Parasympathetic hitchikers from otic ganglion and transmits them to parotid
What does the lingual nerve fibres originate from?
Chorda tympani
How does the chorda tympani join the lingual nerve?
Fine nerve which approaches the lingual nerve from posterior and joints it at a fairly acute angle
What type of nerve is the inferior alveolar nerve?
Mixed motor and sensory nerve
What does the inferior alveolar nerve give off? Where does it enter after?
Mylohyoid branch at some, before entering mandibular foramen.
What is the inferior alveolar nerve accompanied by?
Inferior alveolar artery and vein
What does the inferior alveolar nerve form after branching in the mandible?
Inferior alveolar plexus
Where do the terminal branches of the inferior alveolar nerve form?
Below the first and second premolars